Sparking plug for internal-combustion engines.



M. FERRARIS.

SPARKING PLUG FOR INTERNAL COMBUSTION ENGINES.

' APPLICATION FILED NOV- 6. I911.

1,281,822. Patnted m. 15, 1918.

MARIO rnnaams, UFMILAN, man-Y.

SPARRING PLUG FOR INTERNAL-COMBUSTION ENGINES.

To aZZ whom it may concern Be it known that I, Mauro Framers, en-

' gineerf subject of the Ling of Italy, residing at Mi an, Italy, via -iFestalozzi. No. i, have invented certain new and useful Improve ments inSparking Plugs for internal-Combustion Engines, of which the following is a specification.

This invention has for its object to provide an improved sparking plug for internal combustion engines. lhis improved sparking plug has considerable advantages as regards insulation and upkeep.

A constructional form. of a sparking plug constructed according to this invention is illustrated by way of example in the accompanying drawings in which Figure 1 is a longitudinal section of the improved sparking plug, and e Fig. 2 is an end View of one of the electrodes and of the washer constituting the other electrode. a

Fig. 3 is a plan of the sparking plug, and

Fig. 4- is an elevation thereof.

As shown, the screw-threaded rod 2 constituting one of the electrodes, has fixed to it by means of a nut 1 and a washer 3, one end of the current supply wire, while the lock nut i and the nut 5 serve to press the mica washers 7 that are threaded upon the said electrode and are held in place by its edge 12. 'Betweenthe nut and the mica there is interposed a washer 6. An insulating band or sheath 8 surrounds the rod 2 in such a manner as to fill the space between the said rod and the body of the washers 7.

is a hexagonal body hollow inside and provided outside with ribs; it serves to keep in position the mica washers, the whole of which is pressed and centered by means of a ring 9 over which the edge of the said body 10 is bent after the insulating body 7 denies of this patent may be obtained for Specification of Letters Patent.

Patented flct. 15, 191 8.

Application filed Kovemher G, 1917. Serial No. 2003M.

has been inserted in the latter, and the ring has been placed in position.

A washer 11 having a convex shape on its inner surface, fits internally against the free end of the body 10; it forms a collar around the enlarged portion in which the electrode 2 terminates. A small annular space is left between the collar and the electrode. This washer 11 which is connected mechanically to the body 10 and consequently to the framing of'the engine, forms n the other electrode, and it is between this electrode 11 and the crown of the enlarged part of the electrode 2 that the sparks are produced. 1

It is to be understood-that modifications may be made in the details and construction of the various parts without departing from the nature of this invention.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is A spark plug'of the character described, comprising in combination, a central electrode, means for securing a current supply wire to the same, mica washers threaded upon said electrode, an insulating sheath surrounding said electrode and filling the space between the same and said mica washers, a hexagonal hollow body provided with outside ribs at the lower end of said electrode for keeping the mica washers in place, a rci ng gp which the edge of said body is bent and-a perforated washer on said body constituting the second electrode.

In testimony whereof I have aflixed my signature in presence of two witnesses.

' MARIO FERRARIS.

Witnesses:

ALBERTO PERI, IVAN LAURETSKY.

five cents each, by addressing the Commissioner of Patents, 7

Washington, D. G. 

